Anti-marking Jackets Comprised of Fluoropolymer and Methods of Using in Offset Printing

ABSTRACT

In a printing press having a transfer cylinder for transferring a freshly printed substrate, an anti-marking device is provided. The anti-marking device comprises a flexible jacket comprised of fluoropolymer to engage the freshly printed substrate as it is transferred over the transfer cylinder, the anti-marking device removably attached with free play to the transfer cylinder. In an embodiment, a base cover is installed on the transfer cylinder between the anti-marking device and the transfer cylinder.

CROSS-REFERENCE TO RELATED APPLICATIONS

None.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO A MICROFICHE APPENDIX

Not applicable.

BACKGROUND

In the operation of a rotary offset printing press, freshly printedsubstrates, such as sheets or web material, are guided by transfercylinders or the like from one printing unit to another, and then theyare delivered to a sheet stacker or to a sheet folder/cutter unit,respectively. As used herein, the term “transfer cylinder” includesdelivery cylinders, transfer rollers, support rollers, supportcylinders, delivery wheels, skeleton wheels, segmented wheels, transferdrums, support drums, spider wheels, support wheels, guide wheels, guiderollers, and the like.

The ink marking problems inherent in transferring freshly printedsubstrates have been longstanding. In order to minimize the contact areabetween the transfer means and the freshly printed substrate,conventional support wheels have been modified in the form of relativelythin disks having a toothed or serrated circumference, referred to asskeleton wheels. However, those thin disc transfer means have notovercome the problems of smearing and marking the freshly printedsubstrate due to moving contact between the freshly printed substrateand the projections or serrations. Moreover, the attempts to cover thetransfer cylinder with a cover material and/or minimize the surfacesupport area in contact with the freshly printed substrate materialoften resulted in further problems.

Various efforts have been made to overcome the limitations of thin diskskeleton wheels. One of the most important improvements has beencompletely contrary to the concept of minimizing the surface area ofcontact. That improvement is disclosed and claimed in U.S. Pat. No.3,791,644 to Howard W. DeMoore, incorporated by reference herein in itsentirety, wherein the support surface of a transfer cylinder in the formof a wide wheel or cylinder is coated with an improved ink repellentsurface formed by a layer of polytetrafluoroethylene (PTFE).

During the use of the PTFE coated transfer cylinders in high-speedcommercial printing presses, the surface of the coated cylinders must bewashed frequently with a solvent to remove any ink accumulation.Moreover, it has also been determined that the PTFE coated cylinders donot provide a cushioning effect and relative movement, which arebeneficial.

The limitations on the use of the PTFE coated transfer cylinders havebeen overcome with an improved transfer cylinder having an inkrepellent, cushioning, and supportive fabric covering or the like fortransferring the freshly printed sheet. It is now well recognized andaccepted in the printing industry world-wide that marking and smearingof freshly printed sheets caused by engagement of the wet printedsurface with the supporting surface of a conventional press transfercylinder is substantially reduced by using the anti-marking fabriccovering system as disclosed and claimed in my U.S. Pat. No. 4,402,267entitled “Method and Apparatus for Handling Printed Sheet Material,” thedisclosure of which is incorporated herein by reference.

That system, which is marketed under license by Printing Research, Inc.of Dallas, Tex., U.S.A. under the registered trademark SUPER BLUE®includes the use of a low friction coating or coated material on thesupporting surface of the transfer cylinder, and over which is looselyattached a movable fabric covering. The fabric covering provided ayieldable, cushioning support for the freshly printed side of thesubstrate such that relative movement between the freshly printedsubstrate and the transfer cylinder surface would take place between thefabric covering and the support surface of the transfer cylinder so thatmarking and smearing of the freshly printed surface was substantiallyreduced. Various improvements have been made to the SUPER BLUE® system,which are described in more detail in U.S. Pat. Nos. 5,907,998 and6,244,178 each entitled “Anti-Static, Anti-Smearing Pre-Stretched andPressed Flat, Precision-Cut Striped Flexible Coverings for TransferCylinders”; U.S. Pat. Nos. 5,511,480, 5,603,264, 6,073,556, 6,119,597,and 6,192,800 each entitled “Method and Apparatus for Handling PrintedSheet Material”; U.S. Pat. No. 5,979,322 entitled “Environmentally Safe,Ink Repellent, Anti-Marking Flexible Jacket Covering Having AlignmentStripes, Centering Marks and Pre-Fabricated Reinforcement Strips forAttachment onto Transfer Cylinders in a Printing Press”; and U.S. Pat.No. RE39,305 entitled “Anti-static, Anti-smearing Pre-stretched andPressed Flat, Precision-cut Striped Flexible Coverings for TransferCylinders,” each of which is hereby incorporated by reference herein inits entirety. The above cited patents are all owned by PrintingResearch, Inc. of Dallas, Tex., U.S.A.

SUMMARY

In an embodiment, in a printing press having a transfer cylinder fortransferring a freshly printed substrate, an anti-marking device isdisclosed. The anti-marking device comprises a flexible jacket comprisedof fluoropolymer to engage the freshly printed substrate as it istransferred over the transfer cylinder, the flexible jacket removablyattached with free play to the transfer cylinder.

In another embodiment, a method of maintaining a printing press isdisclosed. The method comprises removing a flexible jacket from thetransfer cylinder, wherein the flexible jacket comprises fluoropolymerand immersing the flexible jacket in a solvent to clean. The methodfurther includes attaching the flexible jacket to the transfer cylinderby a first edge of the flexible jacket, adjusting the free play of theflexible jacket, and attaching the flexible jacket to the transfercylinder by a second edge of the flexible jacket.

In another embodiment, a method of operating a printing press having atransfer cylinder is disclosed. The method comprises printing asubstrate, supporting the substrate during at least a portion of thetransfer of the substrate through the printing press with a flexiblejacket attached to the transfer cylinder with an effective amount offree play, the flexible jacket comprising fluoropolymer, and exposingthe substrate to an artificial radiation source comprising at least oneof an ultraviolet lamp and an infrared lamp.

In another embodiment, in a printing press having a transfer cylinderfor transferring a freshly printed substrate, an anti-marking device isdisclosed. The anti-marking device comprises a flexible jacket coupledto a base cover. The flexible jacket comprises fluoropolymer and engagesthe freshly printed substrate as it is transferred over the transfercylinder. When the anti-marking device is installed over the transfercylinder, the base cover is facing the transfer cylinder and theflexible jacket is facing outwards towards the freshly printedsubstrate. The flexible jacket is coupled to the base cover to promotean effective amount of free play of the flexible jacket when theanti-marking device is installed over the transfer cylinder.

In an embodiment, another method of operating a printing press having atransfer cylinder is provided. The method comprises printing a firstsubstrate and supporting the first substrate during at least a portionof the transfer of the first substrate through the printing press withan anti-marking device comprising a flexible jacket comprised offluoropolymer to engage the freshly printed substrate as it istransferred over the transfer cylinder and a base cover attached to theflexible jacket at two edges to promote an effective amount of free playof the flexible jacket when the anti-marking device is installed overthe transfer cylinder. The method also comprises inserting a non-porousmaterial between the flexible jacket and the base cover from anunattached edge of the anti-marking device and, while the anti-markingdevice remains installed over the transfer cylinder, cleaning theflexible jacket with one of a cleaning agent and a pressroom solvent.The method also comprises, after cleaning the flexible jacket, printinga second substrate and supporting the second substrate during at least aportion of the transfer of the second substrate through the printingpress with the anti-marking device.

These and other features will be more clearly understood from thefollowing detailed description taken in conjunction with theaccompanying drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, referenceis now made to the following brief description, taken in connection withthe accompanying drawings and detailed description, wherein likereference numerals represent like parts.

FIG. 1A is a view of a flexible jacket according to an embodiment of thedisclosure.

FIG. 1B is a sectional view of a flexible jacket according to anembodiment of the disclosure.

FIG. 2A is a schematic side elevational view showing multiple transfercylinders installed at substrate transfer positions in a four colorrotary offset printing press of a type made by Heidelberg DruckmaschinenAktiengesellschaft.

FIG. 2B is a schematic side elevational view showing multiple transfercylinders installed at substrate transfer positions in a four colorrotary offset printing press of the Lithrone Series made by Komori Corp.

FIG. 3 is a perspective view of a transfer cylinder of a type commonlyused on printing presses made by Heidelberg DruckmaschinenAktiengesellschaft.

FIG. 4A is a cross-sectional view of a transfer cylinder taken alongline 15-15 of FIG. 3 having an integrated, anti-marking cover installedthereon.

FIG. 4B is a cross-sectional view of a transfer cylinder of a typecommonly used on Lithrone Series printing presses made by Komori Corp.

FIG. 5 is a flow chart of a method of maintaining a system.

FIG. 6 is a flow chart of a method of printing a substrate.

FIG. 7 is an illustration of an anti-marking device integrating aflexible jacket and a base cover according to an embodiment of thedisclosure.

DETAILED DESCRIPTION

It should be understood at the outset that although illustrativeimplementations of one or more embodiments are illustrated below, thedisclosed systems and methods may be implemented using any number oftechniques, whether currently known or in existence. The disclosureshould in no way be limited to the illustrative implementations,drawings, and techniques illustrated below, but may be modified withinthe scope of the appended claims along with their full scope ofequivalents.

In an embodiment, a transfer cylinder may be at least partially enclosedby a flexible jacket that is installed over the transfer cylinder withan effective amount of free play. In some contexts, the flexible jacketmay be referred to as a net. In some embodiments, a cylinder base cover,hereinafter referred to as a base cover, may be installed over thetransfer cylinder, for example a low friction base cover, and theflexible jacket may be installed on the transfer cylinder over the basecover. In some embodiments, the flexible jacket and the base cover maybe integrated in an assembly, for example with a gripper edge of theflexible jacket and base cover coupled together and a tail edge of theflexible jacket and the base cover coupled together. The integratedflexible jacket and base cover are manufactured to promote an effectiveamount of free play for the flexible jacket when the assembly isinstalled on the transfer cylinder. In other embodiments, however, abase cover may be omitted and the flexible jacket may be installed overthe transfer cylinder with no intervening base cover.

In an embodiment, a plurality of flexible jackets may be installed overthe transfer cylinder with no intervening base cover, the plurality offlexible jackets being installed with an amount of free play that iseffective to promote anti-marking operation of the printing press. In anembodiment, two flexible jackets are installed over the transfercylinder with no intervening base cover, both flexible jackets beinginstalled with an effective amount of free play for promotinganti-marking operation of the printing press. When the printing press isoperated, freshly printed substrates are supported by the flexiblejackets installed over the transfer cylinders as the substrates aretransferred from station to station within the printing press andfinally distributed out of the printing press to a stacking apparatus.In an embodiment, it is thought that the free play of the flexiblejacket promotes the flexible jacket expanding when the transfer cylinderrotates, providing a yieldable, cushioning support for the freshlyprinted substrates and allowing the flexible jacket to adhere to thefreshly printed substrates. Further, it is thought that the free play ofthe flexible jacket promotes the flexible jacket moving with the printedsubstrate, thereby avoiding marking the freshly printed substrate withspurious inking and/or smearing the ink on the freshly printedsubstrate.

The several embodiments of the present disclosure contemplate a flexiblejacket comprised of a fluoropolymer. Fluoropolymers contemplated by thepresent disclosure comprise polytetrafluoroetbylene (PTFE), fluorinatedethylene propylene (FEP), and perfluoroalkoxy (PFA). PTFE is sold underthe trademark TEFLON available from DuPont Corporation and is sold underthe trademark XYLAN available from Whitford. FEP is a copolymer ofhexafluoropropylene and tetrafluoroethylene. Flexible jackets comprisedof fluoropolymer may provide a variety of advantages in differentprinting press environments including extended life, greaterimperviousness to ink penetration, ease of washing and/or cleaning, andgreater resistance to deterioration from exposure to artificialradiation sources. Flexible jackets comprised of fluoropolymer may beable to withstand temperatures of about 400 degrees Fahrenheit, whichmay allow the use of the flexible jackets comprised of fluoropolymer ina wider range of printing environments. While in the following thedescription will commonly refer to PTFE, it is understood that invarious embodiments other fluoropolymers may be used in the place ofPTFE.

In an embodiment, the flexible jacket may be coated with a layer of PTFEon a single surface facing the transfer cylinder or on an inward facingsurface and on an outward facing surface. In another embodiment, theflexible jacket may be at least partially woven of threads comprisingPTFE. For example the flexible jacket may be woven of a mixture ofmetallic threads and threads comprising PTFE. As another example, theflexible jacket may be woven of a mixture of colored threads and threadscomprising PTFE. In another embodiment, the flexible jacket may be wovenof threads that comprise PTFE, for example PTFE coated threads. Inanother embodiment, the flexible jacket may be woven of threads that aremanufactured partly from PTFE, for example a thread manufactured of acomposition comprising PTFE and another suitable material, for examplematerials that promote improved structural strength such as tensilestrength of the threads, that promote desirable stiffness and/or flexurestrength of the flexible jacket, and/or that provide improvedanti-static properties of the threads. In another embodiment, theflexible jacket may be woven of threads consisting essentially of PTFE.In another embodiment, the flexible jacket may be a sheet of continuousPTFE or a sheet mesh of PTFE, for example a sheet of PTFE that has holesor other apertures removed from an otherwise continuous sheet of PTFE.

In an embodiment, the flexible jacket 100 may be woven of threads thatcomprise in the range from 95 percent to 100 percent fluoropolymer (suchas PTFE, FEP, and PFA), in the range from 96 percent to 100 percentfluoropolymer, in the range from 97 percent to 100 percentfluoropolymer, in the range from 98 percent to 100 percentfluoropolymer, in the range from 99 percent to 100 percentfluoropolymer, or in the range from 99.5 percent to 100 percentfluoropolymer. In an embodiment, the flexible jacket 100 may be woven ofthreads comprising fluoropolymer (such as PTFE, FEP, and PFA) and fromgreater than 0 percent up to about 5 percent other material, fromgreater than 0 percent up to 4 percent other material, from greater than0 percent up to 3 percent other material, from greater than 0 percent upto 2 percent other material, from greater than 0 percent up to 1 percentother material, from greater than 0 percent up to 0.5 percent othermaterial. The other materials may be selected to promote structuralstrength of the threads and/or that promote anti-static properties ofthe threads, for example carbon and polyester.

In an embodiment, the flexible jacket 100 may be woven of threads thatcomprise in the range from 95 percent to 100 percent PTFE, in the rangefrom 96 percent to 100 percent PTFE, in the range from 97 percent to 100percent PTFE, in the range from 98 percent to 100 percent PTFE, in therange from 99 percent to 100 percent PTFE, or in the range from 99.5percent to 100 percent PTFE. In an embodiment, the flexible jacket 100may be woven of threads comprising PTFE and from greater than 0 percentup to about 5 percent other material, from greater than 0 percent up to4 percent other material, from greater than 0 percent up to 3 percentother material, from greater than 0 percent up to 2 percent othermaterial, from greater than 0 percent up to 1 percent other material,from greater than 0 percent up to 0.5 percent other material. The othermaterials may be selected to promote structural strength of the threadsand/or that promote anti-static properties of the threads, for examplecarbon and polyester.

It is understood that in some embodiments other fluoropolymers may besubstituted for PTFE in each of the flexible jackets described above.For example, in an embodiment, the flexible jacket may be coated withfluoropolymer, such as PTFE, FEP, and PFA. In an embodiment, theflexible jacket may be at least partially woven of threads comprisingfluoropolymer, such as PTFE, FEP, and PFA. For example the flexiblejacket may be woven of a mixture of metallic threads and treadscomprising fluoropolymer, such as PTFE, FEP, and PFA. As anotherexample, the flexible jacket may be woven of a mixture of coloredthreads and threads comprising fluoropolymer, such as PTFE, FEP, andPFA. In an embodiment, the flexible jacket may be woven of threads thatcomprise fluoropolymer, for example threads coated with fluoropolymersuch as PTFE, FEP, and PFA. In another embodiment, the flexible jacketmay be woven of threads that are manufactured partly from fluoropolymersuch as PTFE, FEP, and PFA, for example a thread manufactured of acomposition comprising fluoropolymer and another suitable material, forexample materials that promote improved structural strength such astensile strength of the threads, that promote desirable stiffness and/orflexure strength of the flexible jacket, and/or that provide improvedanti-static properties of the threads. In an embodiment, the flexiblejacket may be woven of threads that consist essentially offluoropolymer, for example threads that consist essentially of PTFE,FEP, and PFA. In another embodiment, the flexible jacket may be a sheetof continuous PTFE or a sheet mesh of PTFE, for example a sheet of PTFEthat has holes or other apertures removed from an otherwise continuoussheet of PTFE.

Each of these several embodiments of the flexible jacket may havedifferent price points and benefits that make them suitable in somecircumstances and not suitable in other circumstances. In an embodiment,the flexible jacket may be about 8 thousandths (0.008) inch thick (about0.203 mm thick). In another embodiment, the flexible jacket may be about12 thousandths (0.012) inch thick (about 0.305 mm thick). In otherembodiments, the flexible jacket may have a different thickness. In anembodiment, the thickness of the flexible jacket may be determinedsubstantially by the diameter of the threads employed to weave thematerial comprising the flexible jacket. The diameter of the threads maybe selected to achieve a different combination of price point anddurability.

Some of the expected benefits of using flexible jackets at leastpartially comprised of fluoropolymer, such as PTFE, FEP, and PFA,include superior freedom from ink absorption by the flexible jacket,ability to operate in the presence of artificial radiation sources suchas ultraviolet lamps and/or infrared lamps, ability to wash the flexiblejacket and return to service on the printing press, and extended life ofthe flexible jacket. Furthermore, the low coefficient of friction offluoropolymer, such as PTFE, FEP, and PFA, may permit installation ofthe flexible jacket over the transfer cylinder without installing a basecover over the transfer cylinder, thereby saving the cost of the basecover. In an embodiment it may be desired that the coefficient offriction between the flexible jacket and the transfer cylinder and/orthe base cover be less than the coefficient of friction between theflexible jacket and the printed substrate. In an embodiment, the basecover is coated with a fluoropolymer, for example PTFE, FEP, and PFA.

In an embodiment, the base cover has an outwards facing surface (e.g.,the surface faces outwards away from the transfer cylinder when the basecover is installed over the transfer cylinder) encrusted with glassbeads and/or ceramic beads that are adhered to the base cover. Thesurface encrusted with glass and/or ceramic beads in an embodiment maybe coated and/or covered with silicone, with a fluoropolymer, or othermaterial effective to reduce friction. In an embodiment, the base coverhaving a bead encrusted surface may be relatively thinner thanalternative base covers. In one embodiment, for example, the base coverhaving a bead encrusted surface may be about 5 thousandths (0.005) inchthick (about 0.127 mm thick). In other embodiments, however, thethickness of the base cover having a bead encrusted surface may have adifferent thickness, depending on the size of the beads. The relativethinness of the base cover having a bead encrusted surface may haveadvantages in some printing environments, for example when the clearancebetween the transfer cylinder and other moving parts of a printing unit,for example an impression cylinder, is limited. In some circumstances,the thinness of the base cover having a bead encrusted surface maypromote the installation of two flexible jackets over the base cover. Inan embodiment, use of the base cover having a bead encrusted surface maysupport operating a press unit with only the base cover having a beadencrusted surface on the transfer cylinder, without a flexible jacket,for example when a flexible jacket has been damaged and no replacementflexible jacket is in stock.

As discussed above, the flexible jacket is intended to provide ayieldable, cushioning support for the freshly printed side of asubstrate. To achieve this yieldable, cushioning support it is desirablethat the flexible jacket be installed and/or adjusted to have aneffective amount of slack, looseness, and/or free play with respect tothe base cover and/or the transfer cylinder. In an embodiment, theflexible jacket and/or the base cover (when a base cover is employed)may be provided with means for visual alignment to promote adjustment ofthe effective amount of free play of the flexible jacket. In anotherembodiment, however, the flexible jacket may not have means for visualalignment. In another embodiment, the base cover may not have means forvisual alignment. For further details about visual alignment means inthe flexible jacket and/or the base cover, see U.S. patent applicationSer. No. 12/258,225 filed Oct. 24, 2008, and entitled “Offset PrintingTransfer Cylinder Base Cover with Alignment Stripes for PrecisionInstallation of a Flexible Jacket Cover also with Alignment Stripes” byHoward DeMoore, which is hereby incorporated by reference in itsentirety.

The optional means for visual alignment on the flexible jacket and theoptional means for visual alignment on the base cover (when a base coveris employed), singly or in combination, may promote repeatableadjustments based on experience. Additionally, the optional means forvisual alignment on the flexible jacket and the optional means forvisual alignment on the base cover (when a base cover is employed),singly or in combination, may promote ease of conveying instructionsfrom a first experienced press operator to a second less experienced orinexperienced press operator, for example from a remote support centervia a telephone call. In some embodiments, a flexible jacket with meansfor visual alignment may be installed over the transfer cylinder with nointervening base cover, and in this case the visual alignment means onthe flexible jacket may be used on their own to promote adjustment of aneffective amount of free play.

In an embodiment, a plurality of means for visual alignment may bedisposed horizontally on the base cover. As used herein, horizontalindicates that the means for visual alignment on the base cover aresubstantially parallel to the axis of the transfer cylinder when thebase cover is installed over the transfer cylinder. In an embodiment,the means for visual alignment on the base cover are set off from eachother at substantially equal distances, for example by about ¾ inch(about 1.9 cm). In other embodiments, however, the means for visualalignment on the base cover may be set off from each other at equaldistances but different from about ¾ inch (about 1.9 cm). In anembodiment, a plurality of means for visual alignment may be disposedhorizontally on the flexible jacket. As used herein, horizontalindicates that the means for visual alignment on the flexible jacket aresubstantially parallel to the axis of the transfer cylinder when theflexible jacket is installed over the transfer cylinder. In anembodiment, the means for visual alignment on the flexible jacket areset off from each other at substantially equal distances, for example byabout ¾ inch (about 1.9 cm). In other embodiments, however, the meansfor visual alignment on the flexible jacket may be set off by equaldistances but different from about ¾ inch (about 1.9 cm). In otherembodiments, the means for visual alignment may be offset by about thesame amount for both the base cover and the flexible jacket. The meansfor visual alignment, of both and/or either of the base cover and theflexible jacket, may be continuous or interrupted. The means for visualalignment may extend horizontally substantially across the whole of thebase cover and/or flexible jacket. Alternatively, the means for visualalignment may extend only partially horizontally across the base coverand/or flexible jacket.

The optional means for visual alignment on the base cover may bereferred to as visual stripes. The visual stripes on the base cover maybe applied as a line segment or a series of line segments (e.g., adotted line) on the base cover, for example by painting, by lithography,by silk screening, and/or by laser induced marking or scoring, topositively define visual stripes horizontally disposed on the basecover. In another embodiment, different colored threads may be employedto positively define visual stripes horizontally disposed on the basecover. For example, the visual stripes may be defined by periodicallyweaving in one or more threads having a color that contrasts with thecolor of the majority of threads making up the woven material of thebase cover. In another embodiment, the visual stripes may be defined byperiodically weaving in one or more threads having a different diameterthan the majority of threads making up the woven material of the basecover. In another embodiment, the base cover may be woven in a latticepattern that creates substantially horizontal visual stripes in the basecover fabric, for example a herringbone pattern, a checkerboard pattern,a basket weave pattern, and other lattice patterns. As used herein, theterm fabric may refer to a woven material constructed of natural fibersand/or synthetic fibers.

Alternatively, the visual stripes on the base cover may be provided byomitting one or more threads from the woven material of the base cover,for example by omitting one or more weft threads or by omitting one ormore warp threads from a woven base cover. Removing one or more threadsfrom a woven base cover may be said to negatively define visual stripes.The absence of threads from the woven base cover may be discerned by aprint operator by seeing a greater portion of the underlying transfercylinder through the base cover at the location of the missing threads,for example when the transfer cylinder is a bright metal material suchas stainless steel. In some embodiments, a backing strip or backingsheet may be adhered to one side of the base cover to promotediscernment by a print operator of the visual stripes. Alternatively, apacking sheet that promotes discernment of the visual stripes may beplaced around the transfer cylinder beneath the base cover. The backingstrips, backing sheet, and/or packing sheet may have a yellow color, anorange color, a red color, or other color which can be more readilydiscerned through the negatively defined visual stripe. The backingstrips, backing sheet, and/or packing sheet may be a shiny, metallicmaterial. In an embodiment, the transfer cylinder may be painted a colorthat promotes discernment of the visual stripes by a print operator.

Likewise, the optional means for visual alignment on the flexible jacketmay be provided as for the base cover. The means for visual alignment onthe flexible jacket may be referred to as visual stripes. The visualstripes on the flexible jacket may be applied as a line segment or aseries of line segments (e.g., a dotted line) on the flexible jacket,for example by painting, by lithography, by silk screening, and/or bylaser induced marking or scoring, to positively define visual stripeshorizontally disposed on the flexible jacket. In another embodiment,different colored threads may be employed to positively define visualstripes horizontally disposed on the flexible jacket. In anotherembodiment, different diameter threads may be employed to positivelydefine visual stripes horizontally disposed on the flexible jacket. Inanother embodiment, the flexible jacket may be woven in a latticepattern that creates substantially horizontal visual stripes in theflexible jacket woven material, for example a herringbone pattern, acheckerboard pattern, a basket weave pattern, and other latticepatterns.

Alternatively, the visual stripes on the flexible jacket may be providedby omitting one or more threads from the woven material of the flexiblejacket, for example by omitting one or more weft threads or by omittingone or more warp threads from a woven flexible jacket. Removing one ormore threads from a woven flexible jacket may be said to negativelydefine visual stripes. The absence of threads from the woven flexiblejacket may be discerned by a print operator by seeing the base coverthrough the flexible jacket, for example by seeing a visible stripe onthe base cover through the flexible jacket at the area of the missingthread, or by seeing the transfer cylinder through the flexible jacketat the area of the missing thread.

Turning now to FIG. 1A and FIG. 1B, in an embodiment a flexible jacket100 is a fabric, such as a woven material having warp strands 56A andweft strands 56B, have coating 142 that comprises fluropolymer, such asPTFE, FEP, and PFA. The coating 142 may be applied to a woven materialafter weaving has been completed, as by immersing the woven material ina solution, for example, of PTFE resin or material or by applying acoating of PTFE on the woven material. In an embodiment, the coatedwoven material may be heated to a temperature effective to cure thecoating of PTFE. The warp and weft (fill) strands 56 may comprisenatural fibers or synthetic fibers. In another embodiment, however, theflexible jacket 100 does not have coating 142. In an embodiment, atleast some of the warp and weft strands 56 may comprise fluoropolymer,such as PTFE, FEP, and PFA, for example the flexible jacket 100 may bewoven partly from thread that is coated with PTFE. In anotherembodiment, the warp and weft strands 56 may consist of threads that aremanufactured partly from fluoropolymer, such as PTFE, FEP, and PFA, forexample a thread manufactured of a composition comprising PTFE andanother suitable material. In another embodiment, the flexible jacket100 may be woven from threads consisting essentially of fluoropolymer,such as PTFE, FEP, and PFA. In some of these embodiments, the flexiblejacket 100 may be woven both from threads comprising fluoropolymer, suchas PTFE, FEP, and PFA, and other threads, such as metallic threads,metal threads, colored threads, bi-component yarns, such as NEGA-STAT,and other threads. A flexible jacket 100 woven from threads comprisingfluoropolymer may be able to withstand temperatures up to about 400degrees Fahrenheit.

Other alternative configurations of flexible jacket 100 will be readilyapparent to those skilled in the art based upon the description herein,and these alternative configurations are also contemplated by thepresent disclosure. Other embodiments of flexible jackets useful inpracticing the present invention are disclosed in U.S. Pat. Nos.5,907,998; 5,979,322; 6,119,597; and 6,244,178, referenced previouslyand owned by Printing Research Inc. of Dallas, Tex., U.S.A.

In an embodiment, the flexible jacket 100 may be manufactured in aone-step process, wherein the flexible jacket 100 is woven so as toperiodically omit one of either one or more of a weft thread or one ormore of a warp thread from a continuous sheet of woven material. Forexample, the process may omit one or more weft threads every about ¾inch (about 1.9 cm). As another example, the process may omit one ormore warp threads every about ¾ inch (about 1.9 cm). Other spacingsbetween omitted threads may be employed. The process may involve weavingthe flexible jacket 100 from threads comprising PTFE, for examplethreads coated with PTFE or threads consisting essentially of PTFE. Theprocess may further include cutting the continuous sheet of wovenmaterial into separate sheets sized appropriately to form the flexiblejacket 100, which may be referred to as precision cutting the flexiblejacket 100. In an embodiment, the process may include coating the wovenmaterial with PTFE. The PTFE coating may be applied to the wovenmaterial while it is in the continuous form or may be applied to theseparately cut sheets of flexible jacket 100.

For exemplary purposes, the flexible jacket 100 and the optional basecover will be described with reference to the processing of sheetsubstrates. However, it will be understood that the principles of thedisclosure are equally applicable to web substrates. The flexible jacket100 of the present disclosure and the optional base cover may be used incombination with high-speed printing press equipment of the type used,for example, in offset printing. FIG. 2A shows a typical, four coloroffset printing press of the type made by Heidelberg DruckmaschinenAktiengesellschaft, and FIG. 2B shows a four color offset printing pressof the Lithrone Series available from Komori Corp. Referring to FIGS. 2Aand 2B, such equipment includes one or more transfer cylinders 10 forhandling a processed substrate, such as a freshly printed sheet betweenprinting units and upon delivery of the printed sheet to a deliverystacker. The flexible jacket 100 of the present disclosure and theoptional base cover are installed on transfer cylinders 10. As usedherein, the term “processed” refers to various printing methods, whichmay be applied to either side or both sides of a substrate, includingthe application of aqueous inks, protective coatings and decorativecoatings. The term “substrate” refers to sheet material or web material.

Use of the present disclosure, in combination with the transfer cylinder10 at an interstation transfer position (T1, T3) or at a deliveryposition (T4) in a typical rotary offset printing press 12, is believedto be readily understandable to those skilled in the art. In any case,reference may be made to U.S. Pat. Nos. 3,791,644 and 4,402,267, whichdisclose details regarding the location and function of a sheet supportcylinder in a typical multistation printing press. The presentdisclosure may, of course, be utilized with conventional printingpresses having any number of printing units or stations.

Referring to FIGS. 2A and 2B, the press 12 includes a press frame 14coupled on its input end to a sheet feeder 16 from which sheets, hereindesignated S, are individually and sequentially fed into the press. Atits delivery end, the press 12 is coupled to a sheet stacker 18 in whichthe printed sheets are collected and stacked. Interposed between thesheet feeder 16 and the sheet stacker 18 are four substantiallyidentical sheet printing units 20A, 20B, 20C, and 20D which are capableof printing different color inks onto the sheets as they are transferredthrough the press.

As illustrated in FIGS. 2A & 2B, each printing press is of conventionaldesign, and includes a plate cylinder 22, a blanket cylinder 24, and animpression cylinder 26. Freshly printed sheets S from the impressioncylinder 26 are transferred to the next printing press by a transfercylinder 10. The initial printing unit 20A is equipped with a sheetin-feed roller 28 which feeds individual sheets one at a time from thesheet feeder 16 to the initial impression cylinder 26. In an embodiment,the transfer cylinder 10 may be painted a color that promotesdiscernment of negatively defined visual stripes in the optional basecover by a print operator.

The freshly printed sheets S are transferred to the sheet stacker 18 bya delivery conveyor system, generally designated 30. The deliveryconveyor system 30 is of conventional design and includes a pair ofendless delivery gripper chains 32 carrying transversely disposedgripper bars, each having gripper elements for gripping the leading edgeof a freshly printed sheet S as it leaves the impression cylinder 26 atthe delivery position T4. As the leading edge of the printed sheet S isgripped by the grippers, the delivery gripper chains 32 pull the gripperbars and sheet S away from the impression cylinder 26 and transport thefreshly printed sheet S to the sheet delivery stacker 18.

Referring to FIG. 2A, an intermediate transfer cylinder 11 receivessheets printed on one side from the transfer cylinder 10 of thepreceding printing unit 20. Each intermediate transfer cylinder 11,which is of conventional design, typically has a diameter twice that ofthe transfer cylinder 10, and is located between two transfer cylinders10, at interstation transfer positions T1, T2 and T3, respectively. Theimpression cylinders 26, the intermediate transfer cylinders 11, thetransfer cylinders 10, as well as the sheet in-feed roller 28, are eachprovided with sheet grippers which grip the leading edge of the sheet topull the sheet around the cylinder in the direction as indicated by theassociated arrows. The transfer cylinder 10 in the delivery position T4is not equipped with grippers, and includes instead a large longitudinalopening A, which provides clearance for passage of the chain drivendelivery conveyor gripper bars. In some printing press installations, anartificial radiation source, for example an ultraviolet lamp and/or aninfrared lamp, may be mounted to radiate semi-directly or directly ontothe interstation transfer positions T1, T2, and T3. The artificialradiation may be employed to cure and/or set the wet ink on printedsubstrates as they pass through the printing press.

Referring now to FIGS. 3 and 4A, a preferred transfer cylinder 10D isshown for use with the Heidelberg printing press of FIG. 2A. Theflexible jacket 100 and the optional base cover described herein aboveare installed on a transfer cylinder 10D on the last printing unit 20Dof the press 12 in the delivery position (T4) and has a cylindrical rim34, which is supported for rotation on the press frame 14 by a rotatabledelivery shaft 36. The external cylindrical surface 38 of thecylindrical rim 34 has a gap “A” extending longitudinally along thelength of the transfer cylinder 10D and circumferentially betweengripper edge 38A and tail edge 38B, respectively. The transfer cylinder10D is attached to the delivery shaft 36 by longitudinally spaced hubs40, 42 and 44. Additionally, center alignment marks 135 are formed onthe cylinder flanges portions 52, 54 and on the external cylindricalsurface 38 of the cylindrical rim 34, as shown in FIG. 3. The purpose ofthe center alignment marks 135 is to facilitate the precise alignmentand attachment of the flexible jacket 100 and/or the optional base coverto the transfer cylinder 10. In an embodiment, a center alignment mark135 may also be provided on the flexible jacket 100 and/or the optionalbase cover. The center alignment mark 135 may be distinguished from thevisible stripes at least by the fact that the center alignment mark 135is substantially perpendicular to the axis of the transfer cylinder 10while the visible stripes are substantially parallel to the axis of thetransfer cylinder 10.

The hubs 40, 42, and 44 are connected to the cylindrical rim 34 by webs46, 48 and 50, and support the transfer cylinder 10D for rotation on thedelivery shaft 36 of the printing press 12 in a manner similar to themounting arrangement disclosed in U.S. Pat. No. 3,791,644. In theembodiment shown in FIG. 3, the delivery cylinder 10D includes opposedcylinder flanges 52, 54, which extend generally inwardly from thesurface of the cylindrical rim portion 34. The flanges 52 and 54 includeelongated flat surfaces for securing the flexible jacket 100 and theoptional base cover as described below. As described herein, transfercylinders 10 may have alternative configurations for accommodating thevarious means for releasably attaching the flexible jacket 100 and theoptional base cover to the transfer cylinder 10 as described herein.

Referring to FIG. 4B, a cross-sectional view of preferred transfercylinder 10 is shown for use with the Lithrone Series printing press ofFIG. 2B. Transfer cylinder 10 is designed and configured to accept apair of flexible jackets 100, with a first flexible jacket 100 coveringabout one-half of the cylindrical surface 38 of the transfer cylinder 10and a second flexible jacket 100 covering about the remaining one-halfof the cylindrical surface 38. The flexible jacket 100 is releasablyattached to the transfer cylinder 10 at the jacket tail edge and thejacket gripper edge with flat clamp bar 72 held in place with a seriesof spring loaded screws spaced along the length of the clamp bar 72. Insome cases, the flexible jacket 100 is attached by various meansincluding, but not limited to, hook and loop fabric material such asVELCRO that mates adheringly to the flexible jacket 100, an adhesivestrip or tape, and other adhering means. For example, the adhesive stripmay be coupled on one side to the flexible jacket 100 through one of aheating process and a pressure process. In embodiment, a portion of theadhesive strip may be extruded through an edge of the flexible jacket100 to couple the adhesive strip to the flexible jacket 100. Forexample, the extruded portion of the adhesive strip may form end caps orstructures like rivets on the opposite side of the flexible jacket 100to secure the adhesive strip to the flexible jacket 100. The extrudedportion of the adhesive strip may partially form an interlocking matrixon the opposite side of the flexible jacket 100 to secure the adhesivestrip to the flexible jacket 100. In an embodiment, a portion of theflexible jacket 100 along the edge may be abraded to provide a moresuitable mating surface for coupling to a hook and loop fastener, forexample VELCRO. In an embodiment, the flexible jacket 100 may beprecision cut to promote simple installation and proper free playwithout adjustment. It is contemplated that the flexible jacket 100,taught by the present disclosure, may provide extended usage cyclesrelative to known designs for flexible jackets. The flexible jacket 100may be removed, washed, and reinstalled multiple times before theflexible jacket 100 wears out.

The function and operation of the transfer cylinders 10 and associatedgrippers of the printing units 20 are believed to be well known to thosefamiliar with multi-color sheet fed presses, and need not be describedfurther except to note that the impression cylinder 26 functions topress the sheets against the blanket cylinders 24 which applies ink tothe sheets, and the transfer cylinders 10 guide the sheets away from theimpression cylinders 26 with the wet printed side of each sheet facingagainst the support surface of the transfer cylinder 10. Since eachtransfer cylinder 10 supports the printed sheet with the wet printedside facing against the transfer cylinder support surface, the transfercylinder 10 is provided with the flexible jacket 100 and the optionalbase cover as described herein. The flexible jacket 100 and the optionalbase cover are releasably attached to the transfer cylinder 10 by meansfor releasably attaching the flexible jacket 100 and the optional basecover to a transfer cylinder 10. In an embodiment shown in FIG. 4A, theflexible jacket 100 is connected to the transfer cylinder flanges 52 and54 by the hook and loop (i.e., VELCRO) fastener strips 59, 61.Alternatively, the flexible jacket 100 may be, at least partially,connected to the transfer cylinder 10 using adhesive strip, as describedabove. In an embodiment shown in FIG. 4A, the flexible jacket 100 may beattached to the transfer cylinder flanges 52 and 54 by mechanicalmechanisms, for example by mechanical fasteners such as screws;mechanical take up reels or any other forms of mechanical roll up bars(often referred to collectively as reel cylinders); and the like. Uponinstallation of the flexible jacket 100 and the optional base cover, theflexible jacket 100 is movable relative to the transfer cylinder 10 andthe optional base cover as described previously.

In an embodiment, when installed over the transfer cylinder 10, theflexible jacket 100 may extend across the entire width of the transfercylinder 10, for example from an operator edge to a gear edge of thetransfer cylinder 10. In another embodiment, when installed over thetransfer cylinder 10, the flexible jacket 100 may extend across theentire width of the transfer cylinder 10, for example from the operatoredge to the gear edge of the transfer cylinder 10, and around behind theoperator edge and the gear edge, for example to attach to ahook-and-loop fabric strip adhered on to the inner diameter of thetransfer cylinder 10. In another embodiment, when installed over thetransfer cylinder 10, the flexible jacket 100 may not extend across theentire width of the transfer cylinder 10, for example from the operatoredge to the gear edge of the transfer cylinder 10, but may leave anuncovered margin along one or both of the operator edge and the gearedge of the transfer cylinder. In an embodiment, the base cover 300,likewise, may not extend across the entire width of the transfercylinder 10, for example from the operator edge to the gear edge of thetransfer cylinder 10, but may leave an uncovered margin along one orboth of the operator edge and the gear edge of the transfer cylinder 10.In an embodiment, an assembly of the flexible jacket 100 and the basecover may be provided, and the assembly of the flexible jacket 100 andthe base cover may not extend across the entire width of the transfercylinder 10. The narrowing of the flexible jacket 100 and/or the basecover may provide manufacturing cost savings while still providing thedesired support for printed substrates as they pass through the printingpress 20. The width of the flexible jacket 100 and/or the base cover maybe selected to work with the widest substrates that may be printed bythe printing unit 20.

The provision of an uncovered margin along one or both of the operatoredge and the gear edge of the transfer cylinder 10 may reduce and/orattenuate accumulation of ink, grease, oil, and/or other soilingmaterials on the flexible jacket 100 and/or the base cover. In someprinting units 20, transfer cylinders 10 may throw off and/or accumulateink, grease, oil, and/or soiling materials, for example by inkpropagating from the flexible jacket 100 and/or the base cover and bygrease or oil exuding from bearings of the transfer cylinders 10 and/orother moving parts of the printing unit 20. This ink, grease, oil,and/or soiling material may accumulate along the operator edge and/orthe gear edge of the transfer cylinder 10. By leaving an uncoveredmargin, the accumulation of ink, grease, oil, and/or soiling materialalong the operator edge and/or the gear edge of the transfer cylinder 10avoids the fouling of the flexible jacket 100 and/or the base cover andsaves the trouble of cleaning and/or replacing the flexible jacket 100and/or the base cover. Additionally, by reducing exposure of theflexible jacket 100 and/or the base cover, the service life of the basecover 100 and/or the base cover may be extended as a result of reduceddegradation from contact with damaging compositions, such as ink,grease, and/or soiling material.

In an embodiment, the uncovered margins of the transfer cylinder 10 maybe treated to attenuate the movement and/or propagation of the ink,grease, oil, and/or soiling materials inwards from the operator edgeand/or the gear edge of the transfer cylinder 10 towards the flexiblejacket 100 and/or the base cover. This treatment of the transfercylinder 10 may also attenuate the movement and/or propagation of theink, grease, oil, and/or soiling materials outwards to the operator edgeand/or the gear edge of the transfer cylinder 10 and attenuate releaseof the ink, grease, oil, and/or soiling materials to contaminate thefloor and/or the air of the pressroom. In an embodiment, the uncoveredmargins of the transfer cylinder 10 may be abraded or otherwise providedwith a rough and/or unsmooth surface to attenuate propagation of ink,grease, oil, and/or soiling materials inwards from the operator edgeand/or the gear edge of the transfer cylinder 10. In embodiment, theuncovered margins of the transfer cylinder 10 may be provided withgrooves or scoring that comprises troughs and lands, wherein incidentink, grease, oil, and/or soiling materials tend to be constrained withinthe troughs.

In an embodiment, the uncovered margins of the transfer cylinder 10 maybe provided with a surface coating and/or surface treatment that tendsto attract and/or retain the ink, grease, oil, and/or soiling materialsand to attenuate the propagation of the ink, grease, oil, and/or soilingmaterials inwards from the operator edge and/or the gear edge. Thissurface coating and/or surface treatment of the transfer cylinder 10 mayalso attenuate the movement and/or propagation of the ink, grease, oil,and/or soiling materials outwards to the operator edge and/or the gearedge of the transfer cylinder 10 and attenuate release of the ink,grease, oil, and/or soiling materials to contaminate the floor and/orthe air of the pressroom. For example, the uncovered margins of thetransfer cylinder 10 may be provided with a surface coating of anoleophilic material. At least some of the inner portions of the transfercylinder 10 may be provided with a surface coating of oleophobicmaterial. For example, the outermost portion of the uncovered margin ofthe transfer cylinder 10 may be provided with a surface coating of anoleophilic material while an inner portion of the uncovered margin maybe provided with a surface coating of an oleophobic material. Theflexible jacket 100 and/or the base cover may be installed over thetransfer cylinder 10 inside of outer margins of the transfer cylinder 10defined by both the oleophilic surface and the oleophobic surface.

In an embodiment, the base cover may be about as wide as the transfercylinder 10, for example extending from the operator edge to the gearedge of the transfer cylinder 10, while the flexible jacket 100 does notextend from the operator edge to the gear edge of the transfer cylinder10. The outer edges of the base cover, for example the portions of thebase cover not covered by the flexible jacket 100, may have a differentcomposition or a different structure from the portion of the base coverthat is covered by the flexible jacket 100. For example, the outermargins of the base cover may be effective to attract and/or to retainink, grease, oil, and soiling materials and to attenuate the propagationof the same inwards towards the flexible jacket 100. The outer margin ofthe base cover may comprise an outermost portion of oleophilic surfacematerial. In an embodiment, the outer margin of the base cover maycomprise an outermost portion of oleophilic surface material and aninner margin of oleophobic surface material. The outer margin of thebase cover may have a rough surface and/or a surface comprising pits,valleys, or other surface irregularities that tend to attenuate themigration and/or propagation of ink, grease, oil, and/or soilingmaterials inwards to the flexible jacket 100.

Turning now to FIG. 5, a method 200 for maintaining the flexible jacket100 is described. At block 202, the flexible jacket 100 is removed fromthe transfer cylinder 10. While it is expected that the fluoropolymer(such as PTFE, FEP, and PFA) composition of the flexible jacket 100 willrepel ink, nevertheless dried or gummy ink residue may, over manyprinting impressions, accumulate in the flexible jacket 100. When theflexible jacket 100 becomes ink laden or otherwise soiled, it isexpected that the flexible jacket 100 may be removed and washed. Atblock 204, the flexible jacket 100 is immersed in a solvent. The solventmay be any of a variety of substances that, in combination with theteachings of the present disclosure, may be selected readily by thoseskilled in the art including an effective mixture of soap and water. Thesolvent may be common pressroom solvents and/or chemicals such asblanket wash, roller wash, and the like. The solvent may be one or moreof alcohol, acetone, benzene, toluene, and other known cleaningsolvents. In an embodiment, the flexible jacket 100 may soak in thesolvent for a period of time. The soaking in the solvent may besufficient to loosen and at least partially remove accumulated inkand/or soiling materials. At block 206, the solvent is optionallyagitated. By agitating the solvent, the flexible jacket 100 may flex andwork the solvent over and/or through the flexible jacket 100, therebytending to remove ink and/or other soiling matter that has accumulatedon and/or in the flexible jacket 100.

At block 208, the flexible jacket 100 is rinsed to remove solvent fromthe flexible jacket 100 and to flush away loosened ink and soilingmatter. In an embodiment, the flexible jacket 100 may be rinsed by beingremoved from a first vessel containing the solvent and placed in asecond vessel containing a substantially clean solution, for examplewater. The clean solution in the second vessel optionally may beagitated to cause the flexible jacket 100 to flex and work the cleansolution over and/or through the flexible jacket 100. In anotherembodiment, however, the flexible jacket 100 may be treated with a flowof substantially clean solution, for example water, for a period oftime. Other rinsing fluids other than water may be used in someembodiments. In an embodiment, the rinsing of block 208 may be repeatedan effective number of times to incrementally remove solvent from theflexible jacket 100 and to flush away loosened ink and/or soilingmatter. It will be appreciated that the blocks 204, 206, and 208 may bereferred to as washing the flexible jacket 100. In an embodiment, theflexible jacket 100 may be washed in a conventional clothes washer, suchas may be found in many private residences for washing clothing. Atblock 210, the flexible jacket 100 is dried. In an embodiment, theflexible jacket 100 may be air dried, such as by hanging up from a lineexposed to freely moving air. In another embodiment, the flexible jacket100 may be dried in a conventional clothes dryer, such as may be foundin many private residences for drying clothing. In an embodiment, theflexible jacket 100 comprised of fluoropolymer may be able to withstandtemperatures of about 400 degrees Fahrenheit.

At block 212, a first edge of the flexible jacket 100, now washed anddry, is attached to the transfer cylinder 10, for example to the gripperedge of the transfer cylinder 10. At block 214, the free play of theflexible jacket 100 is adjusted. As described above, in an embodiment,an effective amount of looseness in the fit of the flexible jacket 100over the transfer cylinder 10 is preferred to promote the slightadhesion of the flexible jacket 100 to printed substrates as theytransfer through the printing press 12, to promote the flexible jacket100 moving with the printed substrates without sliding contact, therebyavoiding marking the printed substrate. In an embodiment, alignmentmeans on at least one of the flexible jacket 100 and the optional basecover, for example horizontal visual stripes or partial horizontalvisual stripes, may be used to determine the desired amount of free playin the flexible jacket 100. As described above, visual stripes may beprovided in a positive manner by painting, silk screening, lithography,or laser induced marking processes or by using a different coloredthread woven into the flexible jacket 100 and/or optional base cover.Alternatively, visual stripes may be provided in a negative manner byomitting a thread from the weaving of the flexible jacket 100 and/oroptional base cover. At block 216, a second edge of the flexible jacket100 is attached to the transfer cylinder 10, for example a tail edge ofthe transfer cylinder 10. The printing press 12 may now be returned toservice.

Alternatively, in some embodiments, the flexible jacket 100 may bewashed in place, while remaining attached to the transfer cylinder 10.For example, the flexible jacket 100 may be washed with common pressroomsolvents and/or chemicals, for example blanket wash and/or roller wash.In an embodiment, the flexible jacket 100 may be washed with alcohol,acetone, benzene, toluene, xylene, and other known cleaning solvents.

Turning now to FIG. 6, a method 250 of operating a printing press 12 isdescribed. At block 252, a substrate is printed using the printing press12. At block 254, as the printed substrate is transferred through theprinting press 12, the substrate is supported at least in part by theflexible jacket 100. At block 256, the printed substrate is exposed toan artificial radiation source, for example an ultraviolet lamp and/oran infrared lamp. Further, in an embodiment the artificial radiationsource may semi-directly or directly expose the flexible jacket 100 toartificial radiation. Alternatively, in another embodiment, theartificial radiation source may indirectly expose the flexible jacket100 to artificial radiation, either by pointing the artificial radiationsource indirectly towards the transfer cylinder 10 and/or by partialblockage of the artificial radiation source by the printed substrate. Insome embodiments, the artificial radiation may be very intense and suchas to rapidly degrade other materials less resistant to the artificialradiation than fluoropolymer materials (such as PTFE, FEP, and PFA). Theartificial radiation may be sporadic, intermittent, or continuous duringpress operations. For example, the flexible jacket 100 may be radiatedwith sufficient energy to raise the surface temperature of the flexiblejacket 100 to a temperature in the range from about 90 degreesFahrenheit to about 125 degrees Fahrenheit, wherein the flexible jacket100 is able to withstand temperatures up to about 400 degreesFahrenheit. In an embodiment, the artificial radiation source may belocated less than about four feet (about 1.22 m) away but greater thanabout 2 inches (about 5.1 cm) away from the flexible jacket 100. In anembodiment, the fluoropolymer composition (such as PTFE, FEP, and PFA)of the flexible jacket 100 taught by the present disclosure may enablethe flexible jacket 100 to be used in the presence of artificialradiation sources, where the flexible jacket 100 of the prior art mayhave withered, warped, or otherwise been destroyed, posing a possiblefire hazard, in the presence of similar semi-direct or direct artificialradiation.

In some embodiments, the flexible jacket 100 and the optional base coverof the present disclosure may be packaged together and sold as ananti-marking kit for transfer cylinders, for example in a packagecontaining at least one flexible jacket 100 and at least one base cover.In other cases, one base cover may be combined in a package with aplurality of flexible jackets 100, for example six flexible jackets 100,and sold as a kit. In another embodiment, one base cover may be combinedin a package with a plurality of flexible jackets 100, for example twoflexible jackets 100, three flexible jackets 100, four flexible jackets100, five flexible jackets 100, or more than six flexible jackets 100.

Turning now to FIG. 7, an anti-marking device 301 is described. Theanti-marking device 301 comprises a base cover 300 as described aboveattached and/or coupled to the flexible jacket 100 as described above.In an embodiment, the base cover 300 may be removably attached and/orcoupled to the flexible jacket 100. In another embodiment, however, thebase cover 300 may be permanently attached and/or coupled to theflexible jacket 100. As used herein, the term “permanently attached”means that the flexible jacket 100 and base cover 300, where soattached, do not separate without damaging one or the other. Theflexible jacket 100 of the anti-marking device 301 comprisesfluoropolymer, such as PTFE, FEP, and PFA. In an embodiment, theflexible jacket 100 of the anti-marking device 301 is woven of threadscoated with fluoropolymer, such as PTFE, FEP, and PFA. In anotherembodiment, the flexible jacket 100 of the anti-marking device 301 iswoven of threads consisting essentially of fluoropolymer, such as PTFE,FEP, and PTFA. In yet another embodiment, the flexible jacket 100 of theanti-marking device 301 is coated with fluoropolymer, such as PTFE, FEP,and PFA.

The anti-marking device 301 is for installation on the transfer cylinder10 for supporting a printed substrate during transfer through theprinting press 12. When installed over the transfer cylinder 10, thebase cover 300 of the anti-marking device 301 is facing the transfercylinder 10 and the flexible jacket 100 of the anti-marking device 301is facing outwards towards the printed substrate. The anti-markingdevice 301 has a gripper edge 302 and opposing tail edge 304. Theanti-marking device 301 has an operator edge 306 that is positionedtowards the operator side of the printing press 12 when installed andopposing gear edge 308 that is positioned towards the gear side of theprinting press 12 when installed. The anti-marking device 301 may beproduced in a variety of sizes and shapes, most often corresponding tothe dimensions of the wide variety of commercial transfer cylinders 10available. The anti-marking device 301 is typically rectangular inshape.

The flexible jacket 100 may be attached and/or coupled to the base cover300 in a variety of ways. The flexible jacket 100 may be attached to thebase cover 300 along only one edge, for example along only the gripperedge 302 or along only the tail edge 304. The flexible jacket 100 may beattached to the base cover 300 along two edges, for example along thegripper edge 302 and the tail edge 304 or along the gear edge 308 andthe operator edge 306. Alternatively, in another embodiment, theflexible jacket 100 may be attached to the base cover 300 by three orfour of the gripper edge 302, the tail edge 304, the operator edge 306,and the gear edge 308. The attachment along one or more of the edges maybe partial, that is the points of attachment may extend along a portionof an edge and not extend from end-to-end of an edge.

The several alternative configurations may have different advantagesthat recommend their selected use in different environments. Theanti-marking device 301 wherein the flexible jacket 100 is permanentlyattached to the base cover 300 at least partially along one edge only,for example, may promote ease of cleaning the base cover, for examplewhen an unwanted solvent is spilled on the anti-marking device 301. Forexample, in the event of a solvent spill, the unattached edge of theflexible jacket 100 of the anti-marking device 301 may be lifted free ofthe base cover 300 and the transfer cylinder 10, providing access toclean the base cover 300. After cleaning the base cover 300, theflexible jacket 100 may be reattached to the transfer cylinder 10 withthe effective amount of free play. The unattached edge of theanti-marking device 301 may be secured to the transfer cylinder 10 byhook and loop fasteners, for example VELCRO, or other attachment means.

The anti-marking device 301 wherein the flexible jacket 100 is attachedto the base cover 300 at least partially along two opposing edges, forexample along the gripper edge 302 and along the tail edge 304, maypromote cleaning the flexible jacket 100. In an embodiment, the flexiblejacket 100 may be permanently attached to the base cover 300. Forexample, a non-porous material may be inserted from an unattached edge,for example from the operator edge 306 or the gear edge 308, between theflexible jacket 100 and the base cover 300 and the flexible jacket 100may be washed in place over the transfer cylinder 10 with anyappropriate cleaning agent or pressroom solvent. For example, theflexible jacket 100 may be washed with common pressroom solvents and/orchemicals, for example blanket wash and/or roller wash. In anembodiment, the flexible jacket 100 may be washed with alcohol, acetone,benzene, toluene, xylene, and other known cleaning solvents. Theflexible jacket 100 may be washed with a mixture of soap and water. Thenon-porous material may reduce the chances that the cleaning agentand/or pressroom solvent may soil and/or damage the base cover 300.

In an embodiment, a method of operating the printing press 12 having atransfer cylinder 10 comprises printing a first substrate and supportingthe first substrate during at least a portion of the transfer of thefirst substrate through the printing press 12 with the anti-markingdevice 301 comprising the flexible jacket 100 comprised of fluoropolymerto engage the freshly printed substrate as it is transferred over thetransfer cylinder 10 and the base cover 300 attached to the flexiblejacket 100 at two edges, for example at the gripper edge 302 and at thetail edge 304, to promote an effective amount of free play of theflexible jacket 100 when the anti-marking device 301 is installed overthe transfer cylinder 10. The method also comprises inserting anon-porous material between the flexible jacket 100 and the base cover300 from an unattached edge of the anti-marking device 301, for examplefrom one of an operator edge 306 and a gear edge 308, and, while theanti-marking device 301 remains installed over the transfer cylinder 10,cleaning the flexible jacket 100 with one of a cleaning agent and apressroom solvent. The method also comprises, after cleaning theflexible jacket 100, printing a second substrate and supporting thesecond substrate during at least a portion of the transfer of the secondsubstrate through the printing press 12 with the anti-marking device301.

In an embodiment, the flexible jacket 100 may be attached to the basecover 300 by stitching, adhesive, thermal bonding, crimp strips,male-female fasteners, brads, rivets, tension strips, staples, orcombinations thereof. The flexible jacket 100 may be attached to thebase cover 300 so as to provide the desirable effective amount of freeplay in the flexible jacket 100 when the anti-marking device 301 isinstalled on the transfer cylinder 10, thereby relieving an operatorand/or a pressman of the need to adjust the free play of the flexiblejacket 100 when attaching the flexible jacket 100 to the transfercylinder 10 as described above. The anti-marking device 301 may speedthe replacement of the flexible jacket 100 by relieving the operatorand/or pressman of the step of adjusting the free play of the flexiblejacket 100. Additionally, the anti-marking device 301 may overcome theproblem of an inexperienced, and/or an inattentive operator, and/orpressman installing the flexible jacket 100 with either excessive orinsufficient free play.

In an embodiment, two or more flexible jackets 100 may be attached tothe base cover 300 of the anti-marking device 301. As the top-mostflexible jacket 100 wears out, the top-most flexible jacket 100 may beremoved from the anti-marking device 301 and then printing using thenext layer of flexible jacket 100 may resume. Further details ofmultiple layer jackets may be found in U.S. patent application Ser. No.______ filed ______ entitled “Multiple Layer Flexible Jackets for Use inOffset Printing,” by Howard DeMoore et al., which is hereby incorporatedby reference.

While several embodiments have been provided in the present disclosure,it should be understood that the disclosed systems and methods may beembodied in many other specific forms without departing from the spiritor scope of the present disclosure. The present examples are to beconsidered as illustrative and not restrictive, and the intention is notto be limited to the details given herein. For example, the variouselements or components may be combined or integrated in another systemor certain features may be omitted or not implemented.

Also, techniques, systems, subsystems, and methods described andillustrated in the various embodiments as discrete or separate may becombined or integrated with other systems, modules, techniques, ormethods without departing from the scope of the present disclosure.Other items shown or discussed as directly coupled or communicating witheach other may be indirectly coupled or communicating through someinterface, device, or intermediate component, whether electrically,mechanically, or otherwise. Other examples of changes, substitutions,and alterations are ascertainable by one skilled in the art and could bemade without departing from the spirit and scope disclosed herein.

1. In a printing press having a transfer cylinder for transferring afreshly printed substrate, an anti-marking device, comprising: aflexible jacket comprised of fluoropolymer to engage the freshly printedsubstrate as it is transferred over the transfer cylinder, theanti-marking device removably attached with free play to the transfercylinder.
 2. The anti-marking device of claim 1, wherein the flexiblejacket is comprised of at least one of polytetrafluoroethylene (PTFE),fluorinated ethylene propylene (FEP), and perfluoroalkoxy (PFA).
 3. Theanti-marking device of claim 1, wherein the flexible jacket is a wovensheet of material that is coated with fluoropolymer.
 4. The anti-markingdevice of claim 1, wherein the flexible jacket is woven at least in partof threads manufactured using fluoropolymer.
 5. The anti-marking deviceof claim 4, wherein the threads are coated with fluoropolymer before theflexible jacket is woven.
 6. The anti-marking device of claim 4, whereinthe threads are comprised of fluoropolymer.
 7. The anti-marking deviceof claim 4, wherein the threads consist essentially ofpolytetrafluoroethylene (PTFE).
 8. The anti-marking device of claim 4,wherein the threads are comprised of about 99 percentpolytetrafluoroethylene (PTFE) and about 1 percent polyester and carbon.9. The anti-marking device of claim 4, wherein the flexible jacketfurther is woven from at least one of metallic threads, metal threads,bi-conductor yarns, and colored threads.
 10. The anti-marking device ofclaim 4, wherein the flexible jacket further has a gripper edge and atail edge and the flexible jacket further comprises a tape strip alongthe tail edge to promote attaching the flexible jacket to the transfercylinder, wherein the tape strip is secured along a first face to theflexible jacket by at least one of heat treating, pressure treating, andextruding and the second face of the tape strip comprises an adhesive.11. The anti-marking device of claim 1, wherein the flexible jacket hasat least one horizontally disposed means for visual alignment, whereinthe means for visual alignment is used during at least one of attachingthe flexible jacket to the transfer cylinder and adjusting the free playof the flexible jacket.
 12. The anti-marking device of claim 11, whereinthe at least one horizontally disposed means for visual alignmentcomprises a visual alignment stripe.
 13. The anti-marking device ofclaim 12, wherein the flexible jacket is a woven fabric having weftthreads and warp threads and wherein the visual alignment stripe isprovided by the absence of one of at least one weft thread and at leastone warp thread.
 14. The anti-marking device of claim 12, wherein thevisual alignment stripe is applied on the flexible jacket by one of apainting process, a lithographic process, a silk screen process, and alaser induced marking process.
 15. The anti-marking device of claim 11,wherein the flexible jacket comprises a plurality of horizontallydisposed means for visual alignment and wherein each means for visualalignment is separated from adjacent means for visual alignment by asubstantially equal distance of about ¾ inch.
 16. The anti-markingdevice of claim 11, wherein the at least one horizontally disposed meansfor visual alignment extends substantially from a first outer edge ofthe flexible jacket to a second outer edge of the flexible jacket. 17.The anti-marking device of claim 11, wherein the at least onehorizontally disposed means for visual alignment has a length of lessthan about half the width of the transfer cylinder.
 18. The anti-markingdevice of claim 11, wherein the at least one horizontally disposed meansfor visual alignment comprises an interrupted line.
 19. The anti-markingdevice of claim 1, wherein a base cover is installed over the transfercylinder and the flexible jacket is attached to the transfer cylinderover the base cover.
 20. The anti-marking device of claim 19, whereinthe base cover is comprised of fluoropolymer.
 21. The anti-markingdevice of claim 19, wherein the base cover is comprised of beads adheredto an outwards facing surface of the base cover.
 22. The anti-markingdevice of claim 21, wherein the beads are one of glass beads and ceramicbeads.
 23. The anti-marking device of claim 1, wherein the anti-markingdevice is installed over the transfer cylinder with no base coverbetween the transfer cylinder and the anti-marking device.
 24. A methodof maintaining a printing press having a transfer cylinder, comprising:removing a flexible jacket from the transfer cylinder, wherein theflexible jacket is comprised of fluoropolymer; immersing the flexiblejacket in a solvent to clean; attaching the flexible jacket to thetransfer cylinder by a first edge of the flexible jacket; adjusting thefree play of the flexible jacket; and attaching the flexible jacket tothe transfer cylinder by a second edge of the flexible jacket.
 25. Themethod of claim 24, wherein the fluoropolymer is at least one ofpolytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP),and perfluoroalkoxy (PFA).
 26. The method of claim 24, wherein thefluoropolymer is polytetrafluoroethylene (PTFE).
 27. The method of claim24, further including: rinsing the flexible jacket after immersing; anddrying the flexible jacket in a clothes dryer.
 28. The method of claim24, wherein the flexible jacket is woven from threads comprisingfluoropolymer.
 29. The method of claim 24, wherein the flexible jacketis woven from threads consisting essentially of polytetrafluoroethylene(PTFE).
 30. The method of claim 24, wherein the flexible jacket is wovenfrom threads comprised of about 99 percent polytetrafluoroethylene(PTFE) and about 1 percent polyester and carbon.
 31. A method ofoperating a punting press having a transfer cylinder, comprising:printing a substrate; supporting the substrate during at least a portionof the transfer of the substrate through the printing press with aflexible jacket attached to the transfer cylinder with an effectiveamount of free play, the flexible jacket comprised of fluoropolymer; andexposing the substrate to an artificial radiation source comprising atleast one of an ultraviolet lamp and an infrared lamp.
 32. The method ofclaim 31, wherein the fluoropolymer comprises at least one ofpolytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP),and perfluoroalkoxy (PFA).
 33. The method of claim 31, wherein thefluoropolymer is polytetrafluoroethylene (PTFE).
 34. The method of claim31, wherein the flexible jacket is removably attached to the transfercylinder.
 35. The method of claim 31, wherein the radiation incidentupon the flexible jacket is sufficient to raise the surface temperatureof the flexible jacket to a temperature in the range from about 90degrees Fahrenheit to about 125 degrees Fahrenheit, wherein the flexiblejacket is able to withstand temperatures up to about 400 degreesFahrenheit.
 36. The method of claim 31, wherein the artificial radiationsource is located less than about four feet from the flexible jacket andmore than about two inches from the flexible jacket.
 37. The method ofclaim 31, wherein the flexible jacket is woven at least partly fromthreads manufactured using fluoropolymer.
 38. The method of claim 31,wherein the flexible jacket is woven at least partly from threadscomprised of at least about 98 percent polytetrafluoroethylene (PTFE).39. The method of claim 31, wherein the artificial radiation sourceindirectly exposes the substrate.
 40. The method of claim 31, whereinthe artificial radiation source directly exposes the substrate.
 41. Themethod of claim 31, wherein the artificial radiation source exposes thesubstrate to the artificial radiation sporadically.
 42. The method ofclaim 31, wherein the artificial radiation source exposes the substrateto the artificial radiation substantially continuously during operationof the printing press.
 43. In a printing press having a transfercylinder for transferring a freshly printed substrate, an anti-markingdevice, comprising: a flexible jacket comprised of fluoropolymer toengage the freshly printed substrate as it is transferred over thetransfer cylinder; and a base cover coupled to the flexible jacket,wherein when installed over the transfer cylinder the base cover isfacing the transfer cylinder and the flexible jacket is facing outwardstowards the freshly printed substrate and wherein the base cover iscoupled to the flexible jacket to promote an effective amount of freeplay of the flexible jacket when the anti-marking device is installedover the transfer cylinder.
 44. The anti-marking device of claim 43,wherein the flexible jacket is woven of threads manufactured coated withfluoropolymer.
 45. The anti-marking device of claim 43, wherein theflexible jacket is woven of threads consisting essentially offluoropolymer.
 46. The anti-marking device of claim 43, wherein the basecover is coated with fluoropolymer.
 47. The anti-marking device of claim43, wherein the base cover is comprised of beads adhered to an outwardsfacing surface of the base cover.
 48. The anti-marking device of claim47, wherein the beads are one of glass beads and ceramic beads.
 49. Theanti-marking device of claim 43, wherein the fluoropolymer is at leastone of polytetrafluoroethylene (PTFE), fluorinated ethylene propylene(FEP), and perfluoroalkoxy (PFA).
 50. The anti-marking device of claim43, wherein the flexible jacket is comprised of at least about 98percent polytetrafluoroethylene (PTFE).
 51. The anti-marking device ofclaim 43, wherein the base cover is coupled to the flexible jacket alongonly one edge.
 52. The anti-marking device of claim 43, wherein the basecover is coupled to the flexible jacket along a plurality of edges. 53.The anti-marking device of claim 43, wherein the base cover ispermanently attached to the flexible jacket at a gripper edge andwherein when installed over the transfer cylinder the flexible jacket isremovably attached to the transfer cylinder at a tail edge.
 54. A methodof operating a printing press having a transfer cylinder, comprising:printing a first substrate; supporting the first substrate during atleast a portion of the transfer of the first substrate through theprinting press with an anti-marking device comprising a flexible jacketcomprised of fluoropolymer to engage the freshly printed substrate as itis transferred over the transfer cylinder and a base cover attached tothe flexible jacket at two edges to promote an effective amount of freeplay of the flexible jacket when the anti-marking device is installedover the transfer cylinder; inserting a non-porous material between theflexible jacket and the base cover from an unattached edge of theanti-marking device; while the anti-marking device remains installedover the transfer cylinder, cleaning the flexible jacket with one of acleaning agent and a pressroom solvent; after cleaning the flexiblejacket, printing a second substrate; and supporting the second substrateduring at least a portion of the transfer of the second substratethrough the printing press with the anti-marking device.